Manufacture of threads from cupro-ammoniacal solutions of cellulose.



" UNITED STATES BQ O ALBERT LEGOEUROF Rotten, AND PAUL 'nUnoLr, or s'r. AUBIN-JOUXTE-BOULLENG, 'rnmcnnssmnoasxro LE ORINOID SOGIETE ANoNYME,or ROUEN, FRANCE.

MANUFACTURE or THREADS rno vr GUPRO-AMMONIACAL SOLUTIONS or CELLULOSE.

.To ail'whom it mag/ iconce'm:

Be it known that we, ALBERT LEGOEUR, of

and useful Improvements-in the lilanufacture of Threads From Cupro-Ammoniacal Solutions of Cellulose, of which the'following 'isa specification.

This invention relates to improvements in the manufacture of threads from cuproammoniacal solu'tions of cellulose, and more particularly to improvements in or relating to alkaline-precipitating baths employed in the manufacture of threads from cupro;

amtnoniacal solutions of cellulose, whereby the solidity of the thread may be improved,

while the efiiciency of the precipitatingbath is increased and prolonged and the. recovery of the copper from the bath is facilitated. As the cupro-ammoniacalsolution of cellulose is pressed through the spinning cap 'sules' into the alkaline precipitating bath "and formed into threads, the bath gradually acquires a bluis'h color from the presence of copper salts. In a short time the bath becomes so colored that it -is almost impossible to distinguish the blue threads in thesame. and it becomes so difficult for theworkmen' to observe any broken threads and re-attach the broken ends to the bobbin that it is found necessary to recharge the bath with fresh uhcolored liquor long-before the bathbecomes' exhausted. To meet this difliculty it his been proposed to add to the alkalinept saccharose, or aliaiogous substances (viz:

'such alcohols or alcohols with ketone or.

aldehyde groups as are adapted to form loosely combined compounds with bases),

which at an elevated temperature reduce the blue copper salts in solution to metalliccopper or red 'oxi d of copper, which forms a reddish brown deposit against whichthe blue threads can be readily distinguished.

\Ve have discovered that the reduction of the blue copper saltsin solution is effected Specification of Letters Patent.

Application filed June 25, 1910. 'Serial No."56,839.'

cipitating bath glucose,

mamaaan. 3, 1911'.

the quality of the thread, rendering it more solid and resistant tostrain than the thread obtained from alkaline glucose baths. \Ve

sutfices forthe complete reduction at com- 1 have found, for instance, that in a concentrated alkaline bath such'as a bath of caustic soda and carbonateof soda described in British Patent No. 21,191 of 1908, used at a temperature of 40 C. or thereabout, the

presence of-evcn 1.5 er cent. of the commercial 40 per cent. orn'ialdehyde, solution in the precipitating bathsufiices for the nu mediate. reduction of the copper salts which pass into solution during formation of the thread, and causes the copper to deposit metal orlower oxid at'thebottom of the bath, from which it can be easily recovered 1. Process for the manufacture of threads I from cupro-ammoniaeal solutions of cellu-' lose, comprising precipitation of the threads in an alkali'n'ebath containing fOl'll'llCflldG hyde. v r

2. Process for the manufacture of threads from cuproammoniacal solutions of cellulose, comprising precipitation of the threads in a' concentrated alkaline bath, as a bath.

of caustic soda and carbonate of soda, containing about 2 per cent. formic aldehyde,

substantially as specified.

In witness whereof, we have hereunto signed our names in the presence of two subscribing witnesses.

' Y ALBERT LECOEUR.

' PAUL RUDOLF. Vvitnesws:

L. PAPILLON,

MAURICE JDANJoU. 

